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My laboratory is interested in understanding the ecology and population genetics of soil fungi that cause plant disease. The ultimate goal of my research program is to generate science-based knowledge that will result in the deployment of improved disease management approaches that reduce economic losses to plant disease while promoting increased productivity, sustainability and plant health. For many years we have studied the soil fungus Rhizoctonia solani, which is an economically important pathogen of agricultural and forestry crops throughout the world. However, the fungus can also infect non-cultivated species of plants in natural ecosystems and is of ecological importance as a recycler of nutrients in soil. Research conducted in my laboratory has provided a conceptual framework for identifying species of R. solani to better define populations to advance our understanding of the evolutionary history and disease ecology of the fungus. Our research suggests that R. solani is not a single species, but is a genetically diverse assemblage of species that represent an important early diverging and transitional group of the mushroom forming fungi. Current research in my lab is focused on the use of “omic”-based methods to better understand the genetic basis of how R. solani produces microsclerotia, which are structures that promote long-term survival of the fungus in soil in absence of a plant host. More recently we have been involved in the study of Rhizoctonia fungi associated with terrestrial species of orchids. These fungi benefit orchids by increasing seed germination and seedling growth. Information generated from this collaborative research project is being used to develop improved approaches to conserve terrestrial species of orchids native to the US.
Fungi have evolved complex relationships with the environment, animals, insects, plants, and microbes, that have ultimately contributed to their success in space and time. My research aims to gain better insight into the ecological factors and population processes that have contributed to the ability of fungi to cause disease and survive in the absence of a host; this requires a comprehensive understanding of species concepts, genome organization, evolution, and population genetics in the context of plant microbial interactions. This is critical for establishing a foundation of fundamental knowledge that can be translated for the practical management of disease-causing fungi and the promotion of beneficial microorganisms that address societal grand challenges. Research in my laboratory has focused primarily on understanding the disease ecology, genome organization, soil microbiome, population biology, and systematics of the soil fungus Rhizoctonia solani, an economically important pathogen of a wide array of cultivated and native species of plants. Our research has revealed that R. solani is not a single species, but a species complex that represents an early diverging assemblage of fungi that may have given rise to the mushroom forming fungi. These results have provided a conceptual framework for delineating species, examining the genetic diversity and structure of field populations, determining the occurrence and transmission of fungal viruses, and identifying two previously undescribed Rhizoctonia 1) the disease-causing species of Rhizoctonia on agricultural plants and 2) beneficial species of Rhizoctonia on orchids. In addition to Rhizoctonia fungi, research from my lab has contributed to the development of methods for identifying other species of beneficial and disease-causing fungi of plants and more recently animals. My laboratory has also provided valuable bioinformatics, genomic, diagnostic, metabolomic, and microbiome resources for scientists interested in understanding the complex dynamics of different nuclear genomes in Rhizoctonia and other plant/soil associated beneficial and disease-causing fungi. This information has provided foundational knowledge that is key to conducting comparative studies that address fundamental research questions related to host plant adaptation in relation to nuclear genome heterogeneity.